Terminal strip for electromagnets



Nov. 14, 1950 H. E. EPSTEIN 2,529,653

TERMINAL STRIP FOR ELECTRQMAGNETS Filed June 11, 19 7 2 Sheets-Sheet 1 IN VEN TOR.

Nov. 14, 1950 H. E. EPSTEIN TERMINAL STRIP FOR ELECTROMAGNETS 2 Sheets-Sheet 2 Filed June 11, 1947 INVENTOR. /(agc jcf aaiez /z' BY o J W Wmp-xqey Patented Nov. 14, 1950 TERMINAL STRIP FOR ELECTROMAGNETS Hirsch E. Epstein, Chicago, 111., assignor of onehalf to Louis R. Duman chicago, Ill.

Application June 11, 1947, Serial No. 753,863

This invention relates to the construction of electrical circuit components such as chokes and transformers and more particularly to a terminal strip for such devices.

The invention contemplates an extremely simple and effective terminal strip especially suitable for use with small reactances or trans-' formers such as used for components of electronic circuits whereby the cost of manufacturing is considerably decreased at the same time that a more efiicient product is produced.

. The primary object of the invention is to provide a new and improved terminal strip which will enable the attachment of Wires thereto in a manner more efiicient than heretofore, and which will at the same time insulate the wires from the adjacent metal parts of the circuit component with which said terminal is associated.

Other objects of the invention are to provide a novel terminal strip which is made of pliable material so that the circuit component carrying same is readily adaptable for any manner of attachment; to provide a terminal strip which will require no means for attaching same to a circuit component other than already is used in assembling said component; to provide a strip which is extremely simple to manufacture and attach to the circuit component while at the same time being economical; to provide a terminal strip which will serve to protect and insulate the wires attached thereto.

With the foregoing and other objects in View which will appear as the description proceeds, the invention consists of certain novel features of construction hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportion, size and minor details of the structure may be made without departing from the spirit of sacrificing any of the advantages of the invention.

For the purpose of facilitating an understanding of the invention, there are illustrated in the accompanying drawings preferred embodiments of the structure and assembly thereof together with certain progressive views showing the man ner of attaching the terminal strip, from an inspection of which, when considered in connection with the following description, the invention, its mode of construction, assembly and operation, and many of its advantages should be readily understood and appreciated.

Referring to the drawings in which the same characters of reference are employed to indicate 3 Claims. (01.175421) corresponding or similar parts throughout the several=figures of the drawings:

Fig. his a perspective view of a simple transformerhaving terminal strips applied thereto in accordance with my new invention.

Fig. 2 is a perspective view of a pair of flexible sheet members arranged to be fastened together in the formation of my new terminal strip.

Fig. 3 is a perspective view showing the two flexible sheets of Fig. 2 fastened together, a portion of the sheets being broken away to show the construction.

Fig. 4 is a sectional view taken through the transformer of Fig. 1 showing a step in the attachment of my termial strip thereto.

"Fig. 5 is a view similar to Fig. 4 but showing another step in the attachment of the terminal strips.

Fig. 6 is a view similar to Figs. 4 and 5 but showing the completed transformer.

Fig. '7 is a perspective view of a portion of a different type transformer showing a terminal strip associated therewith in accordance with my new invention.

Fig. 8 is a fragmentary sectional view through same.

The reference character In designates generally a small transformer or choke having an outer shell I I of metal which clamps together an assembly of laminations comprising the core l2, a winding l3 having inner and outer insulating and protective layers I 4 and [5, respectively. The shell H includes ears l6 for fastening the transformer ID in place. The winding I3 is shown as composed of primary and secondary windings and hence there are four wire ends which lead out of the winding. These are deslgnated l1, l8, l9, and 20'. It should be understood that there may be more or less wire ends, depending upon the type of winding, and that the invention is not limited thereby.

In mv'invention terminal strips 20 and 2| are attached at opposite ends of the transformer, in a manner to be described, and the wire ends are connected therewith, the pair I 1 and I8 being attachedto the strip 2!! while the pair l9 and 20 is attached to the strip 2|. Both strips 20 and 2| are identical and hence the description of one willsuflice for the both.

The wires 17 and I8 are inserted in the eyelets 22 and 23, respectively, and soldered therein. These eyelets 22 and 23 are now the terminals for the portion of the winding l3 connected to.

the wires I 1 and soldered thereto.

I 8 and external leads may be The eyelets are carried by a act as a single member carrying the eyelets.- The free portions are 25 and 28 each of which serves a different purpose. v

Normally when manufacturing chokes or trans-'-- formers of this type, the shell H is in-theform..v V of a large U into the open end of which the as- H sembled core and winding is inserted. Each of the arms of the shell has a channelled cross section and comprises a base portion 29,: and side portions 35 and 3|. When the assembled corew|-2 and winding i3 is inserted into the shell II, the side portions 30 and 3| are crimped into engagement with thesidesof. the core l2 and the entire circuit component isheld together. Certain lugs are turned over upon the open side of the U, but these are inconsequential insofar as theinvention herein is concerned.

-;Ininstalling a terminal stripupon' such 'adevice in accordance with my invention, theportions 25 and 28 are separated, the one being ,bent back as shown in Fig. 4. The portion. 28 is now inserted under the side-portion 30 in the space 32 formed between itself and theouter lamina-1 tion of the core l2. This is done after the-assembled core and winding 'have'been inserted in the shell, but before the shell has been crimped as described; A'crease or fold is-formed in the terminal strip at 33; Note that prior tocrimping, the terminalstrip is a tripartite member'of threeflaps attached on-a common axis.

' With the entire device assembled 'asshownt-in Fig. 4, the transformer is inserted-in awdie or; otherqtool which will serve to crimp theportions 30 and 3| together. Such a tool may be con-- ventional'and comprises upper and lower jaws 34- -and 35,-respectively; It should benoted that the portion of the jaw 34 which is normally; intended to clear 'the winding" as shown-at '36'willl engage-the strip 24 and flap '25 during -this-op-- eration thereby holding same out of-the-path: of-the jaw 34. The crimping operation causes the shell to be'securely fastened to thecore l2 and obviously the portion 28-being-caught be tween portion 30 and the core,.the terminal strip 20. is permanently held on oneside of the-transformer i0.

- Following the crimping operation, the flap-25is bentdownwardly to 'overlythe top of the portion 30. The strip 24 isalso bent in generally-the same direction as shown in Fig. 6. The flap '25 now insulates the eyeletsZZ-and 23 together'with any wires which may be fastened thereto-from the top of the side portion 3|]. The wires H and it are now threaded through the eye1ets 22 and 23, respectively, soldered, and the excess trimmed, a

It will be seen that the resulting device is provided with a generous terminal strip 20 as opposed to the small metallic lugs usually'attached to such. devices. The terminal strip of my inventionis likewise flexible, will not readily break orteanand can be moved-to assume anydesira able..-po sition. in accordance with the manner oilhave been collectively designated 24 since same applied to a different type of transformer.

connecting same into a circuit. Not only are these advantages achieved, but the addition of the flap 25 prevents the possibility of shorts and protects the wires attached to the terminal strip. By the use of the novel method of attaching my terminal strip, no drilling or tapping or additional stamping of the shell I or the core I2 is required. The method is economical, and eflicient and can speedily be-doneby the same tools used to produce the ordinary choke or transformer.

In Figs. 7 and 8, I have shown my invention as An elongated core ill-carries a plurality of coils or windings 4| and is held in assembly by a clamp member 42 which has a U-shaped formation, includingportions 43 and M. In assembly, the

, terminalstrip 45, which has been assembled from a pair of sheets in the manner shown in Figs. 2 and 3 is associated with the clamp member 42 by inserting the portionJlt between the portion 43 andthe core MI, and then crimping the'clamp member 42 as described in connection with Fig; 5;

The flap 41 corresponding to flap 25 now insulates the grommets or eyelets 48 and 49 carried by the strip 50 from the clamp 42. Wires 5| and 52' are soldered to said eyelets. The advantages enumerated in connection with the application of the invention to transformer ll! apply equally as well to thisstructure.

It is believed that my invention, its construction andassembly, and many of the advantages thereof should readily be understood from the foregoing without further description, and it should also be manifest that the details of the preferred embodiments described are capable of Wide variations within the purview of the invention as described in the appended claims.

What is claimed and desired to secure by Letters Patent of the United States is:

1. In an electromagnetic member which consists of a core having an electrical winding thereon and being formed of a stack of laminations, therebeing 'a metal clamping member having jaws'secured to an exposed end of the stack to hold same in assembly, a terminal strip'of said winding and comprising a pair of flexible insulating sheet members, means fastening same face'to face at an end thereof comprising at least one metal grommet member serving as an electrical terminal, the opposite ends of the sheet member being free, one of said free ends being securely engaged against the surface of said exposed stack end by a jaw of the metal clamp member and'the other free end being arranged to overlie the said jaw to insulate the metal grommet member from the jaw.

2. In an electromagnetic member which consists of a core having an electrical winding thereon'and being formed of a stack of laminations, there being a metal clamping member having jaws secured to an exposed end of the stack to hold same in assembly, a terminal strip comprising a tri-partite member having flaps of insulating material commonly joined along an axis, the outer flaps forming an angle of less than one with the other, one of the outer flaps being secured between one of said jaws and a surface of the exposedstack end, the other outer flap having wire terminal means, and the third flap being interposed between the outer flaps for insulating the second one from the said jaw.

'3; The combination with an electromagnetic circuit element having alaminatedcore, an exposed core:end,'a clamp engaged uponsaidexposed end. and having opposed jaws gripping the 6 REFERENCES CITED The following references are of record in the file of this patent:

5 UNITED STATES PATENTS Number Name Date 1,587,696 Carter June 8, 1926 1,850,105 Higginbottom Mar. 22, 1932 1,981,533 Williams Nov. 20, 1934 10 2,425,443 Soreng Aug. 12, 1947 2,435,093 Mitschrich Jan. 27, 1948 

